I wish I could ask my horse to stop and he'd listen. Transitions are great, both up and down (though canter is a bit rough..) Stopping?? Oh heck no. You could knit a sweater and grow your very own beard before he stopped!
He does this really weird walking 0.4 miles an hour "shuffle".. and then 3 minutes later he'll stop. No matter how much pressure you put on the reins.
It's such a weird concept to him, standing still, slowing down, not running for his life..
Maybe when I get back he'll be better at it. I never did learn how to properly stop so I've just been kind of sitting up taller but sinking down, stopping motion in my hips and slowly close my fingers around the reins. And I know he's paying attention... but I don't think he knows what I mean. Even if I say ho, he won't do it. Even on the ground, I always have to step in front of his shoulder to get him to stop.
And obviously me hauling on the reins doesn't help the situation at all.. but when he does stop, it's a beautiful square ASAP halt. But it rarely happens!